theorem Th47: :: AOFA_A00:52

ex S being non empty non void 10 -connectives strict BoolSignature st
( S is 1-1-connectives & S is 4,1 integer & S is bool-correct & the carrier of S = {0,1} & ex I being SortSymbol of S st
( I = 1 & the connectives of S . 4 is_of_type {} ,I ) )